Frederick deacon marshall



March 5, 1929.

APPARATUS FOR THE D F D. MARSHALL ISTILLATION 0R. HEAT TREATMENT OF CARBONACEOUS OR OTHER MATERIALS Filed April 10. 1926 l fa 3 LU 4 j M I Z I I 5 5 7 y I 7 W V I Q W J: f /4 we? M l- 7 I 0 a 0 a O0 0 0 Us I a T o 1 6 T 15.

INVENTOR fase/cz zmy/yyaslwz ATTORNEY Patented Mar. 5, 192 9.

PATENT FREDERICK BEACON MARSHALL, OF WEYBRIDGE, 'ENGLANT).

APPARATUS FOR DISTILLATION 0R HEAT TREATMENT OF OARBONACEOUS OR QTHER IVIATERIALS.

Application filed April 10, 1926, Serial No.

This invention relates to an apparatus for the distillation of'carbonaceous material of the kind in which two screws of similar pitch are employed forconveying or forcing the material through a casing. lVhere screw conveyors of this type have previously been employeda coarse, deeply-cut thead, usually of the same hand and pitch has been provided in each screw, the screws being arranged another, they are not in contact.

side by side so that one screw fits closely into the other and their threads intermesh thus providing a continuous line of contact between them which has as its object to prevent the material from slipping back along the threads During the distillation or other heat treatment of carbonaceous materialsand in cases where the casing through which the materlal is to be fed is disposed horizontally, 01:18. slightly inclined, the fact that the screws 11 termesh or are in contact with one another is not objectionable owing to the fact that the material does not completely fill the casing,

and a space is left above the material in the lower part of the casing within WlllCll the volatile or other constituents yielded up by the said material cancollect.

i It has not, however, heretofore been feasible to use intermeshing screws WltlllllVBItlcal casings or retorts employed for the purpose of distilling carbonaceous materials, owing to the fact that, as the intermeshmg screws fit clo'sely'within the casing with their threads in contact with one another, while the material also fills completely both sides of the screws, no space is left within which the volatile constituents yielded up during distillation can collect and be withdrawnfrom the casing.

According to the present invention and in the case of a vertical casing or retort for the heat treatment of materials, such as solid carbonaceous materials, where vapours are yielded up during the heat treatment, the threads of a pair of vertically dlsposed screws, instead of intermeshing or being in contact with one another, as heretofore, are spaced apart in such manner that, although the threads are located. and rotate, within one Consequently a space is left between the threads at the axis of the retort within which the vapours yielded up can collect and be withdrawn for the casing, and through this space, if desired, a heating-medium can also be 101,071, and in Great Britain June 5, 1925.

passed. The screws, which are constructed on the Archimedean principle, may revolve in the said direction and the threads may be of the same hand and pitch, i. e., both righthanded or both left-h anded, but right-handed screws must revolve anti-clockwise and lefthanded screws clockwise.

The distance which separates the threads of the cooperating screws may be varied according to the nature of the material undergoing treatment as it must not be sufficiently great to allow the material to pass through the said space, or to slip back along the threads'of the screws. During the rotation 01" the cooperating screws, the material will be forced through the body of theretort in the form of separate segmental rings disposed between the threads or helices of the screws, the rings being broken or interrupted owing to the threads of the screws entering one another at the axis of the retort.

In the accompanying drawings, Fig. 1 is a vertical sectional View of the retort taken along the axis of the propeller screws and shows the screws in elevation. Fig. 2 is a vertical sectional view of the same at line 22 of Fig. 1. Fig. 3 is a horizontal cross section of the retort head at line 3-3 of Fig. 1.

Referring to the drawings, 1 is a vertical retort casing having parallel, straight, sides and between each two straight sides an arcuate side, as shown in Fig. 3. 2 indicates the retort head which is provided with a gas escape port 3 and with an intake 4 for material hi to be treated. The head 2 is preferably supported from the retort casing 1 and is fixed on the upper end thereof at 5. A pair of feed screws are located within the retort, extending lengthwise thereof. Their shafts are indicated by 6 and extend upwardly through the cover plate 7 of the head for connection with suitable mechanism for rotating them. The shafts are provided from near the upper end of the retort casing 1 to its lower end with hubs 8 formed with spiral helices 9. Space between the helices, which are arranged overlapping but out of contact one with another, is indicated by 10 and when this space is filled with material under treatment, the space 10 provides'ample room for ascension of gaseous vapour generated through the material and into the upper portion of the head and thence out through the outlet port 3. A coke receiver 11 of any suitable formiisprovided at its upper end with a closure shown in the form of a hinged door 12 which will be readily understood by all skilled in the art. The upper end of the coke receiver is annular and titted tightly on the under end of the retort casing 1 at 13. The retort casing and coke receiver are shown supported on a supporting member 1a, the coke receiver discharging below the support. Said member 14 is also shown. supporting an exterior casing 15 which extends the whole length of the retort casing 1 and is provided with a combustion chamber G which encloses the retort casing 1.. The upper end of the retort casing is supported by the upward end of the casing 15 which also takes the weight of the head 2. In practice, the shafts 6, which, together with casings 1 and 15, are vertical, are held in suspended position by apparatus not shown, but which will be 16t(llly-U11tle1- stood by all skilled in the art. The cross-sectional contour of the retort casing better tacilitates the upward escape of gas generated and permits the retort casing to receive a greater amount of coal than would be the case if the parallel sides were oppositely and inwardly deflected so as to form a so-called modified 8 cross-section. The coke receiver 11 may be more broadly considered as a dis charge device. The hinge of its door is indicated by 12. The supporting member 1 has an under ledge 14 The upper end of the coke receiver or discharge device 11 is provided with a shoulder 11 which overlaps and is supported by the flanged structure of the supporting member.' The upper end of said member which is fitted tightly to the under end of the retort casing, has a cross-sectional contour corresponding to the cross-sectional contour of the under end of the casing, such under end being tightly socketed within the upper end portion of the receiver or dis charge device. The door 12 is closed during the, retort operation so that an iurush of air into the receiver or discharge device and upwardly into the retort casing is thus prevented. In order that the coke may be discharged substantially laterally, the coke receiver or discharge device 11 is curved outwardly to make its door position projecting beyond a vertical wall of the retort casing.

As shown in Fig. 3, the sides of the metal casing 1 are parallel and consequently two opposed, lengthwise and downwardly extending bights are formed, between the noncurving edges of the feed screw helices, for reception in each bight of a considerable volume of coal or other material to be treated. The helices of the feed screws terminate at the upper portion of the casing corresponding to the upper end portion of the combustion chamber. The head 2 of the casing is wholly above the combustion chamber and forms a chamber for reception of the material Which is fed into this chamberon top of the length of the elongated casing which is en-' closed by the elongated combustion chamber, with the result that as the coke formed is discharged into the coke receiver it form a mass held in place by the closed door 12 and this door forms a resistance to the downward pressure on the coking material so that densifica tion of the coke is effected. During distillation, the gas ascends around and between the screws and up through the material around the screws into head chamber and finallypasses out through the gas escape port. The combustion chamber, that portion of the retort which is enclosed by the combustion chamber, and the feed screw helices are all elongated and are approximately the same length. Said opposed bights extend throughout the length of the feed screws and are eflective factors in the economic treatment of the material.

lVhat I claim is: I

In apparatus of the class described and which includes an elongated, vertical combustion chamber, the combination with a vertical, top, chambered, coal receiving casing having a coal in-take and a gas escape; an elongated, chambered, bottom, coke receiving casing; a door for the discharge end of the coke receiving casing; and, between said top and bottom casing, an intermediate, elongated, vertical retort casing, all the casings communicating one with another; said intermediate retort casing having parallel side walls the inner surfaces of which are flat and curved edge walls; and a plurality of downwardly revoluble feeding feed screws oi? the same hand and pitch, the upper ends oi the helices of the screws terminating at the top of the intermediate retort casing and the bottom ends of said helices terminating at the bottom of said intermediate retort casing; the edge of the helix of one screw being entrant into the space between turns of the helix of an adjacent screw, and the edge of each. helix being spaced apart from and out of contact with its opposed screw; and the edges of the screw helices being spaced apart from the inner wall of said retort casing; and each of the two parallel side walls of the intermediate casing being substantially spaced apart from the edges of the screw helices opposed to the side wall and means for feeding coal into the coal receiving casing above the upper ends of said feed screws, thereby pro-- viding along each lengthwise extending coal receiving-bight formed by inward turns of said helices, a space for a vertical mass of coal throughout the length of each hight; the revoluble feed screws being operative to gather descending coking coal both from the top coal receiving casing and simultaneously from both of said elongated bights and to each feed screw having a shaft extending upwardly above its helix, through the chain- 10 her of the top coal receiving casing and through and outwardly of said casing.

Signed at New York City in the county of New York and State of New York this 12th day of March A. D. 1926.

FREDERICK DEACON MARSHALL. 

